Objective： To explore the value of magnetic resonance imaging （MRI） in diagnosis of occupying lesions in cerebellopontine angle area. Methods： MRI records of 78 patients with pathologically confirmed occupied lesi...Objective： To explore the value of magnetic resonance imaging （MRI） in diagnosis of occupying lesions in cerebellopontine angle area. Methods： MRI records of 78 patients with pathologically confirmed occupied lesions in cerebellopontine angle area were analyzed. Results： Of the 78 cases, 48 （61.5%） were unilateral acoustic neuroma, 5 （6.4%） were bilateral acoustic neuroma, 12 （15.4%） were meningioma, 4 （5.1%） were trigeminal neuroma, 3 （3.8%） were lipoma, 2 （2.6%） were melanoma, and 1 （1.3%） was medulloblastoma. According to the anatomic site, tumor lesion character, and MRI signal, the majority of cerebellopontine angle area tumors were diagnosed accurately. Conclusion： MRI plays an important role in diagnosis of occupying lesions in cerebellopontine angle area.展开更多
Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech ente...Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech enterprise worthy of the name. Recently it has completed the reform of holdings system.展开更多
In 2011, the Occupy Wall Street movement made history as one of the largest grassroots protest events in the United States. Members made frequent use of social media tools, like Twitter, to share information and mobil...In 2011, the Occupy Wall Street movement made history as one of the largest grassroots protest events in the United States. Members made frequent use of social media tools, like Twitter, to share information and mobilize participants. This study uses content analysis to examine the way that Twitter is used to incite, organize, and perpetuate protest movements. 1500 tweets in total were coded for content and linguistic features to provide insight into how Twitter is used to achieve different goals surrounding protest movements, the tonality of the tweets, and the purpose of distributed messages. Our findings indicate that Twitter is a tool primarily used for sharing objective, logistical information, along with opinions, to create a unified community and mobilize individuals to participate in a physical space of protest.展开更多
Drug-induced liver injury(DILI)is defined as injury to the liver caused by exposure to a drug or some drugs.The number of cases suffering from DILI has been increased.There are few clinical features specifically assoc...Drug-induced liver injury(DILI)is defined as injury to the liver caused by exposure to a drug or some drugs.The number of cases suffering from DILI has been increased.There are few clinical features specifically associated with DILI.The recognition and diagnosis of DILI is difficult.In this report,we have described a DILI case caused by herbal remedies.展开更多
Perovskite-type oxide has a general formula ABO3. Both the lattice A- and lattice B-sites can be occupied by two kinds of metallic ions, forming substituted perovskites such as La（1-x）SrxCoO3-d and LaFexCo（1-x）O3....Perovskite-type oxide has a general formula ABO3. Both the lattice A- and lattice B-sites can be occupied by two kinds of metallic ions, forming substituted perovskites such as La（1-x）SrxCoO3-d and LaFexCo（1-x）O3. In the present work, we aim to investigate competitive occupying of Fe（3＋） and Co（3＋） ions into the lattice B-sites of perovskite LaFexCo（1-x）O3 formed under the condition of excess feeding of Fe（3＋） and Co（2＋） ions relative to the La（3＋） ions. For this purpose, standard curve of normalized cell volumes（NCVs） of a defined series of perovskites LaFexCo（1-x）O3 versus the x values was plotted. Lattice occupancy of Fe（3＋） ions at the B-sites of the perovskite LaFexCo（1-x）O3 was then determined from the standard curve. It is proved that Fe（3＋） ions were capable of occupying preferentially into the lattice B-sites of the perovskite crystalline structure.展开更多
Models that predict a forest stand’s evolution are essential for developing plans for sustainable management.A simple mathematical framework was developed that con-siders the individual tree and stand basal area unde...Models that predict a forest stand’s evolution are essential for developing plans for sustainable management.A simple mathematical framework was developed that con-siders the individual tree and stand basal area under random resource competition and is based on two assumptions:(1)a sigmoid-type stochastic process governs tree and stand basal area dynamics of living and dying trees,and(2)the total area that a tree may potentially occupy determines the number of trees per hectare.The most effective method to satisfy these requirements is formalizing each tree diameter and potentially occupied area using Gompertz-type stochastic differential equations governed by fixed and mixed-effect parameters.Data from permanent experimental plots from long-term Lithuania experiments were used to construct the tree and stand basal area models.The new models were relatively unbiased for live trees of all species,including silver birch(Betula pen-dula Roth)and downy birch(Betula pubescens Ehrh.),[spruce(Picea abies),and pine(Pinus sylvestris)].Less reliable predic-tions were made for the basal area of dying trees.Pines gave the highest accuracy prediction of mean basal area among all live trees.The mean basal area prediction for all dying trees was lower than that for live trees.Among all species,pine also had the best average basal area prediction accuracy for live trees.Newly developed basal area growth and yield models can be recommended despite their complex formulation and implementation challenges,particularly in situations when data is scarce.This is because the newly observed plot provides sufficient information to calibrate random effects.展开更多
Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystalliz...Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.展开更多
Gnetophytes are a key group of plant for understanding seed plant phylogeny,partly because of their unique and elusive morphology,such as xylem with vessels,phloem with chaperones,reticular veins,and double fertilizat...Gnetophytes are a key group of plant for understanding seed plant phylogeny,partly because of their unique and elusive morphology,such as xylem with vessels,phloem with chaperones,reticular veins,and double fertilization(Endress,1996).In particular,the ovule bears a membranous integument,the upper part of which extends beyond the seed envelope to form a micropylar tube.Therefore,gnetophytes occupy a unique evolutionary position in the phylogeny of seed plants and apparently represent a transition between angiosperms and other gymnosperms(Ran et al.,2018).Modern gnetophytes consist of only three families:Ephedraceae,Gnetaceae,and Welwitschiaceae,and each family contains only one genus.Ephedraceae(Ephedra L.)are the earliest diverging group of Gnetales,with a total of 70 extant species,and usually occur in cold and arid places in Asia,Europe,northern Africa,western North America and South America(Price,1996;Yang et al.,2017b).展开更多
The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of ...The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of electrides are thus of both scientific and technological significance.Here,we employ first-principles calculations to investigate Mott-insulating Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)electrides with Mn_(5)Si_(3)-type structure,in which half-filled interstitial electrons serve as ions and are spin-polarized.The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons,resulting in spin splitting and a separation between occupied and unoccupied states.The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials.Compared with that in intermetallic electrides,the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak,leading to highly localized magnetic centers and pronounced correlation effects.Therefore,the Mott-insulating electrides Ae_(5)X_(3)have very large indirect bandgaps(0.30 eV).In addition,high pressure is found to strengthen the strong correlation effects and enlarge the bandgap.The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.展开更多
Recently,organic solar cells have attracted the attention of many researchers owing to flexibility,low cost,light weight and large-area applications,and significant improvement in the power conversion efficiency(PCE)....Recently,organic solar cells have attracted the attention of many researchers owing to flexibility,low cost,light weight and large-area applications,and significant improvement in the power conversion efficiency(PCE).In this work,we designed chains from organic compounds as donors and replaced the core unit in each series with a variety of acceptors in order to enhance their optical and electronic characterization and performance for power conversion efficiencies in organic solar cells.We utilized density functional theory(DFT)and time-dependent density functional theory(TD-DFT)to investigate the geometry optimization by using the Gaussian 09 program.Both electronic and optical properties were determined,which involve the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO)levels,the band gap energy,maximum absorption wavelength(λ_(max)),open circuit voltage(V_(oc)),and light harvesting efficiency(LHE).Our evaluation denotes that the small compounds suggested are predicted to exhibit the best performance compared to the first series(SC1),like a lower band gap energy,a lower HOMO energy level,a greater absorption range,and a larger PCE.展开更多
I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six tim...I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six times to fight back but failed.One rainy day,he was tired and sick.When he lay on the ground and was ready to give up,he saw a spider over his head.Six times the spider tried to throw its thread.展开更多
Water lilies are not only highly favored aquatic ornamental plants with cultural and economic importance but they also occupy a critical evolutionary space that is crucial for understanding the origin and early evolut...Water lilies are not only highly favored aquatic ornamental plants with cultural and economic importance but they also occupy a critical evolutionary space that is crucial for understanding the origin and early evolutionary trajectory of flowering plants.The birth and rapid radiation of flowering plants has interested many scientists and was considered‘an abominable mystery’by Charles Darwin.In searching for the angiosperm evolutionary origin and its underlying mechanisms,the genome of Amborella has shed some light on the molecular features of one of the basal angiosperm lineages;however,little is known regarding the genetics and genomics of another basal angiosperm lineage,namely,the water lily.In this study,we reviewed current molecular research and note that water lily research has entered the genomic era.We propose that the genome of the water lily is critical for studying the contentious relationship of basal angiosperms and Darwin’s‘abominable mystery’.Four pantropical water lilies,especially the recently sequenced Nymphaea colorata,have characteristics such as small size,rapid growth rate and numerous seeds and can act as the best model for understanding the origin of angiosperms.The water lily genome is also valuable for revealing the genetics of ornamental traits and will largely accelerate the molecular breeding of water lilies.展开更多
The bulk of the world’s millet crop is produced by India,Nigeria,Niger,Mali,Burkina Faso,Chad,and China.Finger millet(Eleusine coracana(L.)Gaertn),little millet(Panicum sumatrense Roth ex Roem.&Schult.),foxtail m...The bulk of the world’s millet crop is produced by India,Nigeria,Niger,Mali,Burkina Faso,Chad,and China.Finger millet(Eleusine coracana(L.)Gaertn),little millet(Panicum sumatrense Roth ex Roem.&Schult.),foxtail millet(Setaria italica(L.)P.Beauvois)and proso millet(Panicum miliaceum L.)are most commonly found species among various millet varieties.In India,finger millet occupy the largest area under cultivation among the small millets.Finger millet stands unique among the cereals such as barley,rye and oats with higher nutritional contents and has outstanding properties as a subsistence food crop.It is rich in calcium(0.34%),dietary fiber(18%),phytates(0.48%),protein(6%–13%)minerals(2.5%–3.5%),and phenolics(0.3%–3%).Moreover,it is also a rich source of thiamine,riboflavin,iron,methionine,isoleucine,leucine,phenylalanine and other essential amino acids.The abundance of these phytochemicals enhances the nutraceutical potential of finger millet,making it a powerhouse of health benefiting nutrients.It has distinguished health beneficial properties,such as anti-diabetic(type 2 diabetes mellitus),anti-diarrheal,antiulcer,anti-inflammatory,antitumerogenic(K562 chronic myeloid leukemia),atherosclerogenic effects,antimicrobial and antioxidant properties.展开更多
Out-of-hospital cardiac arrest(OHCA)is widely recognized as a global health issue.However,little is known about OHCA epidemiology in the former Union of Soviet Socialist Republics(USSR)territories.[1,2]The15 post-Sovi...Out-of-hospital cardiac arrest(OHCA)is widely recognized as a global health issue.However,little is known about OHCA epidemiology in the former Union of Soviet Socialist Republics(USSR)territories.[1,2]The15 post-Soviet states occupy nearly one-sixth of the land surface of the earth,and the total population exceeds 292 million people.展开更多
The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in ...The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in China(JUNA)phase I experiments presented here.Once commissioned in 2023,CJPL-Ⅱwill occupy a much larger underground space(300000 m^(3)in volume)for conducting experiments and is planned to house CDEX-Ⅱ。展开更多
Commercial space activities are closely related to national politics,economy,and military. Due to the factors such as national security and economic benefits,most countries are actively developing commercial aerospace...Commercial space activities are closely related to national politics,economy,and military. Due to the factors such as national security and economic benefits,most countries are actively developing commercial aerospace.In recent years,with the rapid development of private space companies such as SpaceX Corporation and Blue Origin Company,the cost of commercial space launch has been greatly reduced,which has had a huge effect on the existed international commercial market. Patent is the product of market competition. It is an effective means for international first-class companies to gain a competitive initiative and occupy the market superiority through protecting their intellectual property rights by patents during commercial space cooperation. At present,most of China aerospace enterprises are derived from national defense military units. Patents of national defense military units are the results of intellectual labor,which are characterized by their proprietary,temporal,and regional characteristics. However,due to the characteristics of national defense services,military monopoly,and group nature of property rights,the patent protection of defense units is different from that of ordinary enterprises. The problem of intellectual property protection in commercial space cooperation is more complicated. Therefore,in the fierce competition of international commercial aerospace,how China space companies can use patents to enhance their international competitiveness in commercial space cooperation is worthy of thinking and planning in advance. By analyzing the patent protection strategies and typical cases adopted by domestic and foreign aerospace companies in commercial space cooperation,it is expected to provide a reference for China space enterprises to effectively use patent strategies in commercial and space cooperation and to enhance China commercial aerospace competitiveness.展开更多
“Nezha:Birth of the Demon Child”has been popular all over China in the summer of 2019,which is a milestone in the development of China's cultural industry.Since the reform and open policy,foreign cultures and cu...“Nezha:Birth of the Demon Child”has been popular all over China in the summer of 2019,which is a milestone in the development of China's cultural industry.Since the reform and open policy,foreign cultures and cultural industries have taken root and sprouted in China.There are more and more audience groups in China.The age and scope of the audience are more and more wide,which enriches the spiritual life of Chinese people.However,the local culture and cultural industry need to be developed and protected.Today,with the economic globalization,multi polarization of international politics and more frequent exchanges among countries around the world,how to make our own culture and cultural industry occupy a place in the national spiritual world,and play out the signboard of“Chinese culture”,make Chinese culture and cultural industry“blossom everywhere”,and make more and more people in the world identify with Chinese culture and culture Industry will eventually build China into a socialist cultural superpower with strong economy and technology.There is still a long way to go.In this paper,we will discuss the potential and problems of cultural development in China.展开更多
Pan ××,a school boy aged 13,afterfighting with his school-mate ten days be-fore,felt a pain and swelling on the top ofhis head.The swelling soon increased andextended to occupy about two thirds of thescalp.H...Pan ××,a school boy aged 13,afterfighting with his school-mate ten days be-fore,felt a pain and swelling on the top ofhis head.The swelling soon increased andextended to occupy about two thirds of thescalp.He was sent the same day to the surgi-cal department of a hospital for treatment.Subgaleal hematoma was diagnosed andabout 200 cc of blood was aspirated.A pres-sure bandage was applied and展开更多
The Shubnikov-de Haas(Sd H)oscillation,as evidenced by the oscillating resistivity as a function of magnetic field at sufficiently low temperature,is not uncommon in metals,semimetals and narrow gap semiconductors at ...The Shubnikov-de Haas(Sd H)oscillation,as evidenced by the oscillating resistivity as a function of magnetic field at sufficiently low temperature,is not uncommon in metals,semimetals and narrow gap semiconductors at their conducting state.The origin of Sd H oscillation is associated with Landau quantization,at which the cyclotron orbits of electrons are quantized.In other words,electrons can only occupy discrete energy levels,which are called the Landau levels.As the magnetic field increases,the split,quantized Landau levels move across the Fermi level and hence the material’s transport properties start to oscillate periodically.展开更多
Time-dependent behavior of two kinds of arrays of two coupled quantum-dot cells is examined.Each square cell composed of four quantum dots in the corners contains two electrons and couples with the neighboring cells b...Time-dependent behavior of two kinds of arrays of two coupled quantum-dot cells is examined.Each square cell composed of four quantum dots in the corners contains two electrons and couples with the neighboring cells by Coulomb interactions.The electrons in one cell tend to occupy antipodal dots which results in a cell apolarizationtf.We have investigated the temporal evolution of the polarization of one cell under switch of the polarization of the other cell.Our results demonstrate that,with an adiabatic switch,if two cells are arranged in a line their polarizations will align each other,and if they are arranged in a diagonal way their polarizations will invert each other.However,with an abrupt switch,the above/features for the polarizations of two cells can not hold.The reason is that the system does not stay in its ground state.It is pointed out that the energy dissipation should be considered in order to obtain the appropriate solutions.展开更多
文摘Objective： To explore the value of magnetic resonance imaging （MRI） in diagnosis of occupying lesions in cerebellopontine angle area. Methods： MRI records of 78 patients with pathologically confirmed occupied lesions in cerebellopontine angle area were analyzed. Results： Of the 78 cases, 48 （61.5%） were unilateral acoustic neuroma, 5 （6.4%） were bilateral acoustic neuroma, 12 （15.4%） were meningioma, 4 （5.1%） were trigeminal neuroma, 3 （3.8%） were lipoma, 2 （2.6%） were melanoma, and 1 （1.3%） was medulloblastoma. According to the anatomic site, tumor lesion character, and MRI signal, the majority of cerebellopontine angle area tumors were diagnosed accurately. Conclusion： MRI plays an important role in diagnosis of occupying lesions in cerebellopontine angle area.
文摘Shanghai Yatai Meters & Instruments Co. Ltd. was set up in 1991. It is engaged in research and development of meters and instruments for industrial duration measurement and control system. It is a new hi-tech enterprise worthy of the name. Recently it has completed the reform of holdings system.
文摘In 2011, the Occupy Wall Street movement made history as one of the largest grassroots protest events in the United States. Members made frequent use of social media tools, like Twitter, to share information and mobilize participants. This study uses content analysis to examine the way that Twitter is used to incite, organize, and perpetuate protest movements. 1500 tweets in total were coded for content and linguistic features to provide insight into how Twitter is used to achieve different goals surrounding protest movements, the tonality of the tweets, and the purpose of distributed messages. Our findings indicate that Twitter is a tool primarily used for sharing objective, logistical information, along with opinions, to create a unified community and mobilize individuals to participate in a physical space of protest.
文摘Drug-induced liver injury(DILI)is defined as injury to the liver caused by exposure to a drug or some drugs.The number of cases suffering from DILI has been increased.There are few clinical features specifically associated with DILI.The recognition and diagnosis of DILI is difficult.In this report,we have described a DILI case caused by herbal remedies.
基金financially supported by the National Natural Science Foundation of China(No.21171020)
文摘Perovskite-type oxide has a general formula ABO3. Both the lattice A- and lattice B-sites can be occupied by two kinds of metallic ions, forming substituted perovskites such as La（1-x）SrxCoO3-d and LaFexCo（1-x）O3. In the present work, we aim to investigate competitive occupying of Fe（3＋） and Co（3＋） ions into the lattice B-sites of perovskite LaFexCo（1-x）O3 formed under the condition of excess feeding of Fe（3＋） and Co（2＋） ions relative to the La（3＋） ions. For this purpose, standard curve of normalized cell volumes（NCVs） of a defined series of perovskites LaFexCo（1-x）O3 versus the x values was plotted. Lattice occupancy of Fe（3＋） ions at the B-sites of the perovskite LaFexCo（1-x）O3 was then determined from the standard curve. It is proved that Fe（3＋） ions were capable of occupying preferentially into the lattice B-sites of the perovskite crystalline structure.
基金supported by the Horizon Europe Framework Programme(HORIZON),call Teaming for Excellence(HORIZONWIDERA-2022-ACCESS-01-two-stage)-Creation of the Centre of Excellence in Smart Forestry“Forest 4.0”No.101059985″This research was cofunded by FOREST 4.0-“Ekscelencijos centras tvariai miško bioekonomikai vystyti”(Nr.10-042-P-0002).
文摘Models that predict a forest stand’s evolution are essential for developing plans for sustainable management.A simple mathematical framework was developed that con-siders the individual tree and stand basal area under random resource competition and is based on two assumptions:(1)a sigmoid-type stochastic process governs tree and stand basal area dynamics of living and dying trees,and(2)the total area that a tree may potentially occupy determines the number of trees per hectare.The most effective method to satisfy these requirements is formalizing each tree diameter and potentially occupied area using Gompertz-type stochastic differential equations governed by fixed and mixed-effect parameters.Data from permanent experimental plots from long-term Lithuania experiments were used to construct the tree and stand basal area models.The new models were relatively unbiased for live trees of all species,including silver birch(Betula pen-dula Roth)and downy birch(Betula pubescens Ehrh.),[spruce(Picea abies),and pine(Pinus sylvestris)].Less reliable predic-tions were made for the basal area of dying trees.Pines gave the highest accuracy prediction of mean basal area among all live trees.The mean basal area prediction for all dying trees was lower than that for live trees.Among all species,pine also had the best average basal area prediction accuracy for live trees.Newly developed basal area growth and yield models can be recommended despite their complex formulation and implementation challenges,particularly in situations when data is scarce.This is because the newly observed plot provides sufficient information to calibrate random effects.
基金Project supported by Anhui Natural Science(1808085ME136)。
文摘Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0704)the National Natural Science Foundation of China(Grant No.42272029).
文摘Gnetophytes are a key group of plant for understanding seed plant phylogeny,partly because of their unique and elusive morphology,such as xylem with vessels,phloem with chaperones,reticular veins,and double fertilization(Endress,1996).In particular,the ovule bears a membranous integument,the upper part of which extends beyond the seed envelope to form a micropylar tube.Therefore,gnetophytes occupy a unique evolutionary position in the phylogeny of seed plants and apparently represent a transition between angiosperms and other gymnosperms(Ran et al.,2018).Modern gnetophytes consist of only three families:Ephedraceae,Gnetaceae,and Welwitschiaceae,and each family contains only one genus.Ephedraceae(Ephedra L.)are the earliest diverging group of Gnetales,with a total of 70 extant species,and usually occur in cold and arid places in Asia,Europe,northern Africa,western North America and South America(Price,1996;Yang et al.,2017b).
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12204419 and 12074013)。
文摘The presence of interstitial electrons in electrides endows them with interesting attributes,such as low work function,high carrier concentration,and unique magnetic properties.Thorough knowledge and understanding of electrides are thus of both scientific and technological significance.Here,we employ first-principles calculations to investigate Mott-insulating Ae_(5)X_(3)(Ae=Ca,Sr,and Ba;X=As and Sb)electrides with Mn_(5)Si_(3)-type structure,in which half-filled interstitial electrons serve as ions and are spin-polarized.The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons,resulting in spin splitting and a separation between occupied and unoccupied states.The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials.Compared with that in intermetallic electrides,the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak,leading to highly localized magnetic centers and pronounced correlation effects.Therefore,the Mott-insulating electrides Ae_(5)X_(3)have very large indirect bandgaps(0.30 eV).In addition,high pressure is found to strengthen the strong correlation effects and enlarge the bandgap.The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.
文摘Recently,organic solar cells have attracted the attention of many researchers owing to flexibility,low cost,light weight and large-area applications,and significant improvement in the power conversion efficiency(PCE).In this work,we designed chains from organic compounds as donors and replaced the core unit in each series with a variety of acceptors in order to enhance their optical and electronic characterization and performance for power conversion efficiencies in organic solar cells.We utilized density functional theory(DFT)and time-dependent density functional theory(TD-DFT)to investigate the geometry optimization by using the Gaussian 09 program.Both electronic and optical properties were determined,which involve the lowest unoccupied molecular orbital(LUMO)and the highest occupied molecular orbital(HOMO)levels,the band gap energy,maximum absorption wavelength(λ_(max)),open circuit voltage(V_(oc)),and light harvesting efficiency(LHE).Our evaluation denotes that the small compounds suggested are predicted to exhibit the best performance compared to the first series(SC1),like a lower band gap energy,a lower HOMO energy level,a greater absorption range,and a larger PCE.
文摘I read a story from an interesting book.The story said that once there was a king in Scotland whose name was Robert Bruce.His homeland was occupied by the king of England.He was driven out of his land.He tried six times to fight back but failed.One rainy day,he was tired and sick.When he lay on the ground and was ready to give up,he saw a spider over his head.Six times the spider tried to throw its thread.
基金This work was supported by the National Natural Science Foundation of China(81502437)a start-up fund from the Fujian Agriculture and Forestry University to LZ We acknowledge Dr Xianxian Yu from Xuchang University for providing the N.colorata picture in Figure 1.
文摘Water lilies are not only highly favored aquatic ornamental plants with cultural and economic importance but they also occupy a critical evolutionary space that is crucial for understanding the origin and early evolutionary trajectory of flowering plants.The birth and rapid radiation of flowering plants has interested many scientists and was considered‘an abominable mystery’by Charles Darwin.In searching for the angiosperm evolutionary origin and its underlying mechanisms,the genome of Amborella has shed some light on the molecular features of one of the basal angiosperm lineages;however,little is known regarding the genetics and genomics of another basal angiosperm lineage,namely,the water lily.In this study,we reviewed current molecular research and note that water lily research has entered the genomic era.We propose that the genome of the water lily is critical for studying the contentious relationship of basal angiosperms and Darwin’s‘abominable mystery’.Four pantropical water lilies,especially the recently sequenced Nymphaea colorata,have characteristics such as small size,rapid growth rate and numerous seeds and can act as the best model for understanding the origin of angiosperms.The water lily genome is also valuable for revealing the genetics of ornamental traits and will largely accelerate the molecular breeding of water lilies.
文摘The bulk of the world’s millet crop is produced by India,Nigeria,Niger,Mali,Burkina Faso,Chad,and China.Finger millet(Eleusine coracana(L.)Gaertn),little millet(Panicum sumatrense Roth ex Roem.&Schult.),foxtail millet(Setaria italica(L.)P.Beauvois)and proso millet(Panicum miliaceum L.)are most commonly found species among various millet varieties.In India,finger millet occupy the largest area under cultivation among the small millets.Finger millet stands unique among the cereals such as barley,rye and oats with higher nutritional contents and has outstanding properties as a subsistence food crop.It is rich in calcium(0.34%),dietary fiber(18%),phytates(0.48%),protein(6%–13%)minerals(2.5%–3.5%),and phenolics(0.3%–3%).Moreover,it is also a rich source of thiamine,riboflavin,iron,methionine,isoleucine,leucine,phenylalanine and other essential amino acids.The abundance of these phytochemicals enhances the nutraceutical potential of finger millet,making it a powerhouse of health benefiting nutrients.It has distinguished health beneficial properties,such as anti-diabetic(type 2 diabetes mellitus),anti-diarrheal,antiulcer,anti-inflammatory,antitumerogenic(K562 chronic myeloid leukemia),atherosclerogenic effects,antimicrobial and antioxidant properties.
文摘Out-of-hospital cardiac arrest(OHCA)is widely recognized as a global health issue.However,little is known about OHCA epidemiology in the former Union of Soviet Socialist Republics(USSR)territories.[1,2]The15 post-Soviet states occupy nearly one-sixth of the land surface of the earth,and the total population exceeds 292 million people.
基金the National Natural Science Foundation of China(Grant No.11490560)the CNNC innovation fundthe CAS instrument fund。
文摘The China Jinping Underground Laboratory phaseⅡ[1](CJPL-Ⅱ)is the expansion project following the success of CJPL-I.A temporary usage in the year 2020–2021 enabled the Underground Nuclear Astrophysics Experiment in China(JUNA)phase I experiments presented here.Once commissioned in 2023,CJPL-Ⅱwill occupy a much larger underground space(300000 m^(3)in volume)for conducting experiments and is planned to house CDEX-Ⅱ。
文摘Commercial space activities are closely related to national politics,economy,and military. Due to the factors such as national security and economic benefits,most countries are actively developing commercial aerospace.In recent years,with the rapid development of private space companies such as SpaceX Corporation and Blue Origin Company,the cost of commercial space launch has been greatly reduced,which has had a huge effect on the existed international commercial market. Patent is the product of market competition. It is an effective means for international first-class companies to gain a competitive initiative and occupy the market superiority through protecting their intellectual property rights by patents during commercial space cooperation. At present,most of China aerospace enterprises are derived from national defense military units. Patents of national defense military units are the results of intellectual labor,which are characterized by their proprietary,temporal,and regional characteristics. However,due to the characteristics of national defense services,military monopoly,and group nature of property rights,the patent protection of defense units is different from that of ordinary enterprises. The problem of intellectual property protection in commercial space cooperation is more complicated. Therefore,in the fierce competition of international commercial aerospace,how China space companies can use patents to enhance their international competitiveness in commercial space cooperation is worthy of thinking and planning in advance. By analyzing the patent protection strategies and typical cases adopted by domestic and foreign aerospace companies in commercial space cooperation,it is expected to provide a reference for China space enterprises to effectively use patent strategies in commercial and space cooperation and to enhance China commercial aerospace competitiveness.
文摘“Nezha:Birth of the Demon Child”has been popular all over China in the summer of 2019,which is a milestone in the development of China's cultural industry.Since the reform and open policy,foreign cultures and cultural industries have taken root and sprouted in China.There are more and more audience groups in China.The age and scope of the audience are more and more wide,which enriches the spiritual life of Chinese people.However,the local culture and cultural industry need to be developed and protected.Today,with the economic globalization,multi polarization of international politics and more frequent exchanges among countries around the world,how to make our own culture and cultural industry occupy a place in the national spiritual world,and play out the signboard of“Chinese culture”,make Chinese culture and cultural industry“blossom everywhere”,and make more and more people in the world identify with Chinese culture and culture Industry will eventually build China into a socialist cultural superpower with strong economy and technology.There is still a long way to go.In this paper,we will discuss the potential and problems of cultural development in China.
文摘Pan ××,a school boy aged 13,afterfighting with his school-mate ten days be-fore,felt a pain and swelling on the top ofhis head.The swelling soon increased andextended to occupy about two thirds of thescalp.He was sent the same day to the surgi-cal department of a hospital for treatment.Subgaleal hematoma was diagnosed andabout 200 cc of blood was aspirated.A pres-sure bandage was applied and
文摘The Shubnikov-de Haas(Sd H)oscillation,as evidenced by the oscillating resistivity as a function of magnetic field at sufficiently low temperature,is not uncommon in metals,semimetals and narrow gap semiconductors at their conducting state.The origin of Sd H oscillation is associated with Landau quantization,at which the cyclotron orbits of electrons are quantized.In other words,electrons can only occupy discrete energy levels,which are called the Landau levels.As the magnetic field increases,the split,quantized Landau levels move across the Fermi level and hence the material’s transport properties start to oscillate periodically.
基金Supported by Shandong Distinguished Middle-aged and Young Scientist Encourage and Reward Foundation of China。
文摘Time-dependent behavior of two kinds of arrays of two coupled quantum-dot cells is examined.Each square cell composed of four quantum dots in the corners contains two electrons and couples with the neighboring cells by Coulomb interactions.The electrons in one cell tend to occupy antipodal dots which results in a cell apolarizationtf.We have investigated the temporal evolution of the polarization of one cell under switch of the polarization of the other cell.Our results demonstrate that,with an adiabatic switch,if two cells are arranged in a line their polarizations will align each other,and if they are arranged in a diagonal way their polarizations will invert each other.However,with an abrupt switch,the above/features for the polarizations of two cells can not hold.The reason is that the system does not stay in its ground state.It is pointed out that the energy dissipation should be considered in order to obtain the appropriate solutions.
